He was taken to the Royal Sussex County Hospital in Brighton, where his mother Reme Keightley, 30, and his father Dean Oliver were at his bedside. Lewis was undergoing treatment for his facial injuries, but police said they are not considered to be life-threatening.

His great-aunt Jane Keightley said: "All I know is that Kona snapped at Lewis but I really don't know any more details at the moment.

"Kona got him on the side of the mouth. I haven't seen Lewis but I know that he has been up watching telly and taking drinks. He is a brave little soldier."

The family, who live on an estate in the market town, had Kona - not a banned breed of dog - since he was a puppy.

A spokesman for Sussex Police said Kona was destroyed with the consent of the parents.

Ms Keightley said the family own another dog of the same breed which is now to be rehomed.

She said: "Kona had never shown any aggression towards anyone before. He has been there since he was born and played with the children and chased them. This is the first time that he decided to snap."

Lewis has a 13-year-old sister. Asked how Lewis's parents were feeling, the great-aunt said: "They are absolutely devastated."